Adrenomyeloneuropathy (AMN) is an X-linked inherited metabolic rare disease caused by mutations in the ABCD1 gene, with an incidence rate of only 1 in 50,000. Currently, it is regarded as a special type of adrenoleukodystrophy (ALD), and AMN is the most dominant disease subtype affecting adult patients. Due to the special phenomenon of skewed X-inactivation, female heterozygotes may also have spinal cord neuropathy. Such mutations can lead to the accumulation of very long chain fatty acids (VLCFA) in the blood and organs, mainly resulting in demyelination of the central nervous system and lesions in the adrenal cortex. As the disease progresses, the strength of the lower limbs and the passive range of motion of the ankle joints of patients will gradually decline. The deterioration of hip flexor muscle weakness is closely associated with a slower walking speed and an increased degree of disability. Most patients will also experience peripheral nerve involvement and impairment of vibration sensation. Hypertonia of the lower limbs will gradually develop into a decline in both muscle strength and muscle tone, and finally progress from spastic paralysis to flaccid paralysis. However, the current commonly used treatment regimens for AMN still have deficiencies, and it is necessary to seek effective treatment methods to alleviate patients' symptoms and improve their quality of life.
Spinal Cord Stimulation (SCS) involves implanting a thin electrode (either strip-shaped or needle-shaped) into the epidural space within the spinal canal at the corresponding spinal segments, adjacent to the posterior columns of the spinal cord. The electrode is then connected to a nerve stimulator implanted subcutaneously in the iliac region, and electrical pulses are used to stimulate the conduction of the posterior columns of the spinal cord and the sensory neurons in the posterior horns for treatment purposes. This blocks the transmission of pain signals from the spinal cord to the brain, preventing them from reaching the cerebral cortex, thereby achieving the goal of pain control. Previous studies have demonstrated that, in addition to having significant therapeutic effects in analgesia, SCS has also been investigated in aspects such as the recovery of lower limb function in paraplegia and the recovery of upper limb function in hemiplegia after stroke, and it has improved the corresponding motor dysfunctions to a certain extent. For the problem of motor dysfunction in AMN, there is currently no good treatment method, and spinal cord stimulation may serve as a potential treatment approach. Based on the above, this study attempts to further explore the potential therapeutic effect and related treatment mechanisms of SCS on AMN through evaluating the efficacy of SCS in treating motor disorders of muscle tone and strength in the lower limbs of patients with AMN.
In the study, 10 patients with AMN will be recruited. After patients are enrolled in the group, preoperative evaluations will be conducted. And after the first evaluations of motor function, neurological assessment and other relevant examinations, the implantation of lumbar spinal cord nerve stimulator and pulse generator will be carried out in our hospital. After the completion of the implantation surgery, depending on the patients' recovery status, they will be transferred to each center for subsequent rehabilitation treatment within one to two weeks, and then the electrical stimulation treatment will be initiated by turning on the device. Before turning on the device, the second corresponding examinations and evaluations will be conducted. The third and fourth corresponding examinations and evaluations will be carried out one week and four weeks after turning on the device, respectively. Patients will be discharged four weeks after turning on the device, and then return to the hospital for the fifth and sixth corresponding examinations and evaluations four weeks and six months after discharge, respectively. Through the statistical analysis of self-controlled comparison before and after the trial, the efficacy and safety of SCS in improving lower limb motor dysfunction in patients with AMN will be evaluated.
